After some advice on which way to go.
HA server 1: Installed in my house
HA server 2: installed in my car
HA server 3: installed in my van
The car and van are not always connected to the internet.
What I’m wanting is when they are all back either in wifi range, or back when they reconnect to the internet, for them to share all the data logged during the outage period. Essentially I’m wanting to be able review data that was captured on HA server 1, whilst logged into HA server 2 etc. Is this possible?
Also, I have a separate MQTT broker running on all three, however for some connected clients I would like to be control across all 3 brokers. As an example, the broker installed on the HA server in the car controls my BLUETTI Ac200max, allowing me to log all the data but also turn on/off. I would also like to be able have full control of this on the other two HA Servers, is this also possible?
Why do you think the home server would be accurate over the others? If they are trying to record charge/discharge cycles on the Bluetti, then the car would have the most accurate data.
Trying to get HA to know about entities that exist in other instances to the extent that it will display their history but won’t try to interact with them seems like it will get messy quite quickly. My first thought would be to use a full database backend (postgres/maria rather than sqlite), use the replication tools from the DB engine to push all 3 databases into a combined repository, and then use something like grafana to report and present the data.
If you are using Mosquitto as your broker it can selectively forward events between multiple brokers, check out the section on Bridges in the manual.